Sissy Squat

What the sissy squat actually trains

A sissy squat is a knee dominant squat performed with the hips held in extension, where you rise onto the balls of your feet, bend the knees and lean the torso backwards while keeping a straight line from knee to shoulder.

The quadriceps do essentially all of the work, and one head in particular is the reason to do it.

Three of the four quadriceps heads, the vastus lateralis, medialis and intermedius, cross only the knee. The rectus femoris crosses both the knee and the hip. That means its length depends on what the hip is doing as well as what the knee is doing, and in an ordinary squat, where the hip flexes as the knee flexes, the rectus femoris shortens at one end while it lengthens at the other. It stays roughly the same length throughout and does comparatively little.

A sissy squat breaks that. By holding the hip extended while the knee flexes deeply, you lengthen the rectus femoris at both ends at once. It ends up in a stretched position under tension, which is not something any conventional squat, leg press or lunge achieves.

Pedrosa and colleagues found training at long muscle lengths produced favourable hypertrophy outcomes compared with short length work, and Schoenfeld and Grgic's review reached a similar conclusion about range of motion generally. The sissy squat is the practical application of that principle to the one quadriceps head that conventional squatting neglects.

Setting up and executing

Hold a rack upright or a doorframe with one hand for balance, not to pull with.

Stand with the feet hip width apart and rise onto the balls of your feet.

Squeeze the glutes hard to lock the hips straight. This is the whole exercise. If the hips fold at any point, you are doing an ordinary squat.

Bend the knees and let them travel a long way forward while the torso leans back, so that your thigh and your torso stay in one line.

Descend slowly, over about three seconds, until the front of your thighs are strongly stretched. Stop before the hips break their straight line, which will be much sooner than you expect at first.

Extend the knees to pull yourself back up, finishing standing tall with the glutes squeezed.

The mistakes that cost you the most

Letting the hips bend is the fault that removes the entire point of the exercise. The moment the hip flexes, the rectus femoris shortens at the top and the stretched position disappears. Squeeze the glutes throughout and stop the rep when they let go.

Dropping into the bottom throws away the best part. The stretched position under tension is what you came for, and while Schoenfeld and colleagues found eccentric and concentric training produce broadly comparable hypertrophy when volume is equated, the descent is still half the rep. Three seconds down.

Going too deep too soon is the practical error. Full knee flexion with the hip extended is a position most people have never loaded, and the tissue around the knee needs weeks to adapt. Start easy and add range.

Pulling with the support arm turns it into an assisted movement without you noticing, which is fine deliberately and useless accidentally.

And adding load before the range is solid is premature. Most people cannot complete a full range sissy squat at bodyweight.

Sets, reps and rest by goal

Lower reps than you would expect for a bodyweight exercise, because it is genuinely hard.

For muscle gain, three sets of eight to fifteen with ninety seconds rest. For strength, three sets of six to ten with two minutes. In a fat loss phase, three sets of twelve to twenty with a minute, though at that point you have probably reduced the range to make the reps possible.

Progress by range first, getting a little deeper each week until you can descend to a strong stretch under control. Then by tempo, taking four or five seconds down. Then, and only then, hold a plate at your chest.

Start conservatively. Two sets of six at a comfortable range is a sensible first exposure.

Schoenfeld and colleagues found a dose response between weekly hard sets and hypertrophy, though this is accessory work and three to four sets a week is plenty alongside your main squatting.

Refalo and colleagues found stopping short of failure produces comparable growth to going to failure, which matters here because the failure rep on a sissy squat is the one where your hips fold and your knees take an uncontrolled load.

Where it fits in your split

After the main squatting, as quadriceps accessory work.

On push, pull and legs it goes late on legs day. On a bro split it finishes the quads. On an upper and lower split it follows the compound work. On a full body programme it is worth including only if quads are a specific priority. On a bodyweight programme it is the hardest quadriceps movement available and deserves a place.

The reason to include it is narrow but real. If you squat, leg press and lunge, your vastus heads are well covered and your rectus femoris is not. This fills that gap, and there are very few other exercises that do.

The reason to skip it is equally legitimate. It is fiddly, hard to load progressively, and if your knees dislike the position there is no technique fix. A reverse Nordic curl or a reclined leg extension covers the same ground more easily.

Once or twice a week, three to four total sets, is the sensible dose.

Variations worth knowing

The assisted sissy squat uses both hands on a support and takes some of your weight through the arms, which is the correct starting point for most people.

A sissy squat bench anchors the ankles in a padded frame, which removes the balance problem entirely and lets you use a fuller range with more control. If your gym has one, use it.

The reverse Nordic curl performs the same hip extended knee flexion from a kneeling position. It is easier to control, easier to scale and, for most people, the better version of this idea.

The weighted sissy squat holds a plate against the chest once bodyweight through a full range is comfortable, which is the only real loading progression available.

The leg extension isolates the quadriceps on a machine, and with the torso reclined it also lengthens the rectus femoris at the hip.

And a heels elevated squat is the general purpose knee dominant option, more loadable but without the hip extension that makes the sissy squat distinctive.

What the evidence says

Pedrosa and colleagues found training at long muscle lengths produced favourable hypertrophy outcomes compared with training at short lengths, which is the central argument for an exercise that places the rectus femoris in a lengthened position under load.

Schoenfeld and Grgic reviewed range of motion and muscle development and concluded that fuller ranges generally produce better growth, particularly where the extra range occurs at longer muscle lengths.

Hartmann and colleagues reviewed knee joint loading across squat depths and found no evidence that deep knee flexion damages the knee in trained individuals, which is the reason not to repeat the claim that sissy squats destroy your knees. What is true is that the position is unfamiliar and the tissue needs time to adapt.

Escamilla's analysis of knee biomechanics during the squat describes how joint forces change with knee angle, which supports building the range gradually rather than starting at full depth.

Schoenfeld and colleagues compared concentric and eccentric training and found broadly similar hypertrophy when volume was equated, which supports controlling the descent without treating it as magic.

Schoenfeld and colleagues on weekly volume and Refalo and colleagues on proximity to failure supply the programming, and the latter matters here because the last hard rep is where the hips fold.

Common questions

Do sissy squats damage your knees?

No, though the caveat is real. Hartmann and colleagues reviewed knee loading across squat depths and found no evidence that deep knee flexion harms healthy knees. What is true is that this position puts high force through the knee at an angle most people never train, so it feels uncomfortable if you rush it. Build the range over weeks. If discomfort persists, use a reverse Nordic curl instead.

Why not just do leg extensions?

You can, and if you have a machine it covers similar ground with far less fuss. The sissy squat's advantage is that it needs no equipment and trains the pattern standing. Its disadvantage is that it is awkward to load and to scale. If your gym has a leg extension, the machine is easier to progress.

What makes it different from a normal squat?

The hips. In a normal squat, the hips and knees flex together, so the rectus femoris shortens at the hip while it lengthens at the knee and never reaches a long position. A sissy squat holds the hips extended, so the muscle is stretched at both ends at once. That is the entire reason the exercise exists.

How is it different from a reverse Nordic curl?

Very little, mechanically. Both flex the knee with the hip extended and both target the rectus femoris at length. The reverse Nordic is done kneeling, which removes the balance problem and makes the range easier to control. If you only want one, take the reverse Nordic and use a support to scale it.

How much range should I use?

As much as you control with the hips locked straight. For most people starting out that is a surprisingly small amount, and that is fine. Add a little each week. The rep where your hips fold is the rep past your current range, and it is the one worth avoiding.